import 'dart:ffi';

main() {
  print("hello world");

  var a = 123;
  var b = 123;
  if (a == b) {
    print("真");
  } else {
    print("假");
  }

  var l6 = ["你好", "账号"];
  print(l6);

  var map = {};
  var set = new Set();

  if (map is Map) {
    print("is map type");
  }
  print(printInfor("张三"));

  Animal animal = new Animal(){
  };
}

printInfor(var name, [var age]) {
  if (age != null) {
    return "$name--$age";
  }
  return "$name";
}

abstract class Animal {
  eat();
}
